The field of the disclosure relates generally to a gear and corresponding method of manufacturing gears for use in epicyclic gear assemblies and, more particularly, to a gear and method of manufacturing a gear having reduced roller element stress when subject to a load.
Aircraft engines and similar turbine engines typically include a plurality of gearboxes including a plurality of gears. Some known gearboxes include epicyclic gear assemblies, which typically include an outer ring gear, a central or sun gear, and a plurality of planet gears disposed between the outer ring gear and the central gear and configured to engage both the ring gear and the central gear. During operation, a drive applies a rotational force to at least one of the ring gear, the plurality of planet gears, and the central gear, thereby inducing rotation of one or more of the other epicyclic gear assembly gears. Some known planet gears include a bearing pin and a roller element bearing disposed between the bearing pin and a gear rim of the planet gear.
During operation, a planet gear of an epicyclic gear assembly is subjected to forces by the sun gear and the ring gear to which the planet gear is coupled. The forces experienced by the planet gear generally induces a portion of the planet gear rim to become partially loaded and to deform in response to the applied load. For example, forces from the sun and the ring gear generally result in a pinching of the planet gear rim such that a first portion of the planet gear rim subject to stresses induced by the forces partially elongates while a second, unloaded portion remains substantially unchanged. In planet gears having roller element bearings, the roller element bearings are generally disposed in a roller element gap defined between the gear rim and a bearing pin. Accordingly, deformation of the gear rim may lead to uneven loading of the roller elements, decreasing their useful life and increasing the time and cost of maintaining corresponding epicyclic gear assemblies.